Field of the Invention
The present invention relates to apparatus and methods of installing a line on a downhole tool.
Description of the Related Art
A packing element is used on a downhole tool of a tubing string to create zonal isolation, for example, between production zones during hydraulic fracturing and during the production of an oil or gas well. In some implementations, various types of lines may be run along the tubing string and may need to pass the isolation provided by the packing element. Typically, the line can be a fiber optic cable used to convey data, or the line can be a hydraulic control line or the like.
One way to pass the line past the packing element involves positioning the line between the tool's mandrel and the internal dimension of the packing element. In this arrangement, the sealing abilities of the packing element are not particularly affected, and the packing element can help protect the line during run in. However, for some types of lines, such as continuous feed-through lines, integrating the line in this arrangement requires the packing element and the line to be assembled on the rig before deployment, which can be tedious and can delay operations. In addition, being able to use a continuous feed-through line that does not have any connectors and the like can be complicated. Overall, integrating a line on the packing element requires special considerations that typically equate to rig time, cost, and a restriction in the type of feed-through mechanism employed.
One method of passing a continuous control line is using split gauge rings that are assembled on the packer on the rig floor, or gauge rings that are only partially assembled on the rig floor with addition of steel plates with bolts. Split gauge rings can be expensive in their manufacture. Also, split gauge rings for a large tool size may become problematic to handle due to their weight. Gauge rings utilizing plates and bolts are also problematic as they may not have sufficient strength to securely hold the control lines in certain applications and well environments.
Further, split gauge rings are complex to manufacture, which may result in excessive material loss and high manufacturing costs. The bolts for affixing the halves of the gauge ring about the mandrel may be susceptible to failure under high pressures. These bolts might also fail in configurations where the bulk of the gauge ring is sent to the field affixed to the mandrel, but the control line is secured by a secondary plate against the main gauge ring. Multi-pieced gauge rings on the rig floor may also see issues with parts getting lost or damaged. In larger diameter tools, weight may become an issue as safety regulations may limit how much a worker can lift.
There is a need, therefore, for a more effective way to retain a control line that passes through a downhole tool, such as a packer.